The present invention is generally directed to an apparatus for feeding insert materials from one or more insert storage devices to an insert processing machine such as a mail processing machine. More particularly, the present invention is directed to an insert hopper having components which improve the operation of the insert hopper.
Mail insertion machines automate many mail processing tasks. These tasks include handling documents, invoices, cards and other types of inserts, inserting a single insert or group of inserts into envelopes, sealing the envelopes, and accumulating the resulting mail packages. A key component of the mail insertion machine is the insert hopper or magazine, which is used typically to store inserts and prepare the inserts for extraction or feeding into other stations of the mail insertion machine.
One type of insert feed station that can be used in a mail insertion machine is illustrated in FIG. 1. An example of this insert feed station, generally designated 10, is disclosed in U.S. Pat. No. 4,369,962 to Spiro. Insert feed station 10 includes an insert hopper generally designated 15 and an insert extraction means generally designated 20. Insert hopper 15 includes a front guide plate 15A, a rear guide wall or back stop 15B, and a bottom support 15C. Front guide plate 15A, back stop 15B and bottom support 15C cooperate to generally define an insert hopper area 15xe2x80x2 in which a stack of inserts 25 can be loaded. Insert hopper 15 has a bottom opening 15D defined between bottom support 15C and front guide plate 15A through which the lowermost insert of insert stack 25 can be extracted from insert hopper 15. In mail insertion machines adapted to process a plurality of different inserts, several insert feed stations 10 with associated insert hoppers 15 and insert extraction means 20 can be disposed in series along the course of the mail insertion machine.
One or more air nozzles such as air nozzle 32 communicating with a compressed air source (not shown) are mounted to front guide plate 15A. Air is blown through air nozzle 32 between the lowermost sheet and next-to-lowermost inserts of insert stack 25, thereby xe2x80x9cfluffingxe2x80x9d these inserts to ensure that an insert hopper suction cup 34 (or a plurality thereof) disposed below insert hopper 15 engages and separates only the lowermost insert. Suction cup 34 is attached to vacuum tubing 36 through which vacuum is provided from a vacuum source (not shown). Suction cup 34 is mounted at the end of a reciprocating arm 38 pivotably mounted to a shaft 39.
Insert extraction means 20 includes an arcuate vacuum surface 42 generally disposed below suction cup 34 and attached to a reciprocating arm 44 pivotably mounted to a shaft 45. Vacuum surface 42 includes a plurality of orifices 42A communicating with a plenum chamber 42B (shown in phantom) and ultimately with a vacuum source (not shown). After rotating upwardly and engaging the lowermost insert, suction cup 34 retracts downwardly to separate the lowermost insert from insert stack 25. Vacuum surface 42 then engages the lowermost insert and rotates about shaft 45 to bring the lowermost insert into engagement with the remaining portions of insert extraction means 20.
The remaining portions of insert extraction means 20 include a pair of oppositely rotating nip rollers 46A and 46B, each of which are driven by respective belts or chains 47A and 47B and pulleys or sprockets 48A and 48B, and an actuating roller 52. Actuating roller 52 is pivotably mounted to the end of a rocker arm 54. Rocker arm 54 itself is pivotably mounted to a reciprocating arm 56 which moves synchronously with respect to vacuum surface 42. The rocking motion of rocker arm 54 is effected through a rotating cam 58 and a reciprocating cam follower 58A. At the urging of cam 58, cam follower 58A translates downwardly through the bore of an extension member 56A of reciprocating arm 56, thereby lifting actuating roller 52, and retracts with the biasing assistance of a spring 58B. Actuating roller 52 can be used to urge the lowermost insert against vacuum surface 42 and/or between nip rollers 46A and 46B. Nip rollers 46A and 46B drive the lowermost sheet toward the next station of the mail insertion machine. The next station can be another insert feed station 10 for feeding a different type of insert, an envelope stuffing station, or the like.
Another type of insert feed station is illustrated in FIG. 2. An example of this insert feed station, generally designated 100, is disclosed in U.S. Pat. No. 5,975,514 to Emigh et al. Insert feed station 100 includes insert hopper generally designated 15 and an insert extraction means generally designated 120. As in the prior example, insert hopper 15 includes front guide plate 15A, back stop 15B, bottom support 15C, insert hopper area 15xe2x80x2 and bottom opening 15D between bottom support 15C and front guide plate 15A through which the lowermost insert of insert stack 25 can be extracted from insert hopper 15. Suction cup 34 is also provided. In this case, a pneumatically driven cylinder 135 and mechanical linkages 135A are used to reciprocate suction cup 34 through its positions. In FIG. 2, however, the approaches taken for insert separation and extraction are different.
Insert feed apparatus 100 in FIG. 2 includes an insert separator foot 132 that is reciprocated by linkage 133A and pneumatically driven cylinder 133. A tip 132A of insert separator foot 132 rotates toward insert hopper 15 and into a position between the trailing edges of the lowermost insert and next-to-lowermost insert. Tip 132A ensures that only the lowermost insert is engaged and separated by suction cup 34. Insert extraction means 120 is characterized by a gripper jaw assembly 146 attached at the end of a picker arm 148. Picker arm 148 rotates in reciprocating fashion about a drive shaft 149 journaled in a bearing 152 at the end of an angled arm 154. Gripper jaw assembly 146 includes a stationary foot 146A and a movable gripper jaw 146B. Gripper jaw 146B is actuated by a pneumatically driven cylinder 155 interposed between pivotal attachments 155A and 155B mounted to picker arm 148 and gripper jaw 146B, respectively. Gripper jaw assembly 146 thus operates in synchronous cycles with suction cup 34 and insert separator foot 132 to extract the lowermost insert from insert stack 25.
FIG. 2 also illustrates an insert track conveyor 160 on which a group of inserts or an extracted insert such as insert I travel to downstream stations of the mail insertion machine. Insert track conveyor 160 is driven by a drive chain 160A, and insert I is guided by pusher fingers or flights 160B extending upwardly from drive chain 160A. An insert track hold-down foot 165 (or a plurality thereof) can be used to secure inserts I in proper positions on insert track conveyor 160 during successive track advancements. In the example shown, insert track hold-down foot 165 is pivotably mounted on a shaft 166 and actuated through a linkage 167A and pneumatically driven cylinder 167.
Insert feed apparatuses such as station 10 shown in FIG. 1 and station 100 shown in FIG. 2 generally perform well for their intended purposes within the context of mail insertion machines. Current insert hopper designs, however, present some limitations that affect the overall utility of insert feed apparatuses and their associated mail insertion machines.
One limitation relates to the working stack height of insert stack 25 loaded into insert hopper 15, i.e., the maximum number of inserts that can be loaded into insert hopper 15 without impairing the operation of the particular insert extraction means used. For any given insert feed apparatus, the working stack height depends upon the type of insert, the finish provided on the surface of the insert, the size of the insert, and the weight of the insert. End users of mail insertion machines often find that the working stack height of insert hoppers 15 provided with the machines is less than the height, or capacity, suggested by the physical attributes of insert hoppers 15. For example, insert hopper 15 might initially be observed as large enough to hold 100 inserts of a given type, but in practice could hold a maximum of only 50 inserts of that type to ensure error-free operation.
The chief limiting factor for the working stack height is the magnitude of the gripping force or effort required to extract the lowermost insert from the bottom of insert stack 25. This extraction force is dictated largely by the coefficient of friction between the lowermost insert and bottom support 15C, and by the downward force vector resulting from the cumulative weight of insert stack 25. A maximum working stack height for a given type of insert can be empirically indicated at the point where the insert extraction means begins to xe2x80x9cmissxe2x80x9d or fail to pull inserts away from insert hopper 15. A maximum height can also be indicated at the point where the insert extraction means engages the inserts successfully but the requisite extraction force begins to exceed the tensile strength of the insert material, with the result that the engaged or gripped portion of the inserts are torn away. Such feeding errors interfere with the smooth, synchronized process flow of mail insertion machines, limit the operating times of insert feed apparatuses, and in turn increase the time required to process a given mail handling job.
A second limitation relates to the registration of the lowermost insert against one or more of the boundaries of insert hopper 15, especially against front guide plate 15A. The lowermost insert must be properly registered in order to bring it into alignment with the gripping means during the extraction procedure and thereby prevent misfeeds and other errors. Improper registration of insert stack 25 is an ongoing problem in current insert hopper designs. The problem is particularly acute with the lowermost insert. The lowermost insert is often misaligned with respect to the remaining portion of insert stack 25. Moreover, if the lowermost insert had been improperly sheared during some upstream cutting process, a portion of the next-to-lowermost insert of insert stack 25 can be exposed to suction cup 34. This can result in the well-known xe2x80x9cdouble-insertxe2x80x9d type of misfeed. Hence, in current insert hopper designs, improper registration of the lowermost insert is frequently a random, uncontrolled event.
A third limitation relates to the existence of warped inserts loaded into insert hopper 15. Warped inserts are difficult to register within insert hoppers 15 and thus difficult to feed without ensuing errors.
Measures taken heretofore to address the limitations of current insert hopper designs have enjoyed limited success. One approach has been to tilt or mount insert hopper 15 at an incline (e.g., 8xc2x0-10xc2x0 from the vertical) in order to reduce the vertical component of the downward force vector imposed by the weight of insert stack 25. This approach by itself has generally been considered to be inadequate by those skilled in the art. Another approach recognizes that an xe2x80x9coptimum break pointxe2x80x9d can be found for the lowermost insert of insert stack 25. The optimum break point is generally defined as the point at which the lowermost insert bends in response to the application of vacuum by suction cup 34 to align the lowermost insert for extraction by the insert extraction means. The optimum break point can be adjusted by making the position of bottom support 15C adjustable in the insert feed direction, which accordingly renders the area of insert hopper bottom opening 15D adjustable. Because of the afore-mentioned problems with friction of bottom support 15C and registration of the lowermost insert within insert hopper 15, the ability to adjust bottom support 15C in current designs is frequently ineffective to prevent misfeeds. Such misfeeds occur even when the working stack height is reduced, and thus the provision of adjustable bottom supports 15C has not improved the loading capacity of current insert hoppers 15. Moreover, the discovery of an optimum break point for insert stack 25 cannot address the problems associated with warped inserts located randomly within insert stack 25.
An increase in the working stack height would permit a greater number of inserts to be loaded into insert hopper 15, and consequently permit an insert feed apparatus to feed inserts over a longer period of time before a reloading or refilling of insert hopper 15 is required. This, in turn, would result in a reduction in the down-time occasioned by the reloading of insert hopper 15 and a concomitant increase in the overall efficiency of the mail insertion machine. Furthermore, improvements in registration of the lowermost insert as well as entire insert stack 25 would result in a more successful prevention of misfeeds, even in the case of warped inserts.
The present invention is provided to address these and other problems associated with insert hoppers such as those depicted in FIGS. 1 and 2, as well as other devices used in the bottom-feeding of inserts or documents from stacks employed in conjunction with insert or document handling apparatuses.
Accordingly, the present invention includes two primary solutions for improving insert hoppers. The first is the provision of a bottom support having a reduced-friction outer surface. The second is the provision of wedges disposed at a trailing edge of an insert stack loaded into the insert hopper and supported by the bottom support. The reduced-friction bottom support and wedges can be used in conjunction with common types of tilted or untilted insert hoppers in a variety of insert handling applications. The novel bottom support and wedges operate to reduce the coefficient of friction between the bottom support and the lowermost insert of the insert stack. This in turn reduces the magnitude of force or effort required by extraction means provided with the insert hopper to extract inserts from the insert stack and feed the inserts to downstream operations. The wedges reduce the area of contact between the lowermost insert and bottom support, and urge the lowermost insert into proper registration with a front guide plate of the insert hopper to ensure proper alignment with the extraction means. The wedges also force or shape a warped insert into a corrected profile sufficient to permit error-free extraction from the insert hopper. The reduced-friction bottom support and wedges additionally increase the effectiveness of adjustment means utilized to support the optimum break point of inserts, as well as the effectiveness of tilted insert hoppers. As a result, an improved insert hopper is provided with either the reduced-friction bottom support, the wedges, or both, and can accommodate an insert stack height four to five times larger than that of conventional insert hoppers.
In one embodiment according to the present invention, an insert hopper is provided for storing a stack of inserts and enabling seriatim extraction of the lowermost insert of the insert stack from a lower location of the insert stack along an insert feed direction. A support deck defines a lower boundary of an insert hopper area in which the insert stack can be loaded. A front registration member extends upwardly in relation to the support deck and defines a front boundary of the insert hopper area. The front registration member registers respective leading edges of the insert stack loaded in the insert hopper area. A backstop member extends upwardly in relation to the support deck and defines a rear boundary of the insert hopper area. The backstop member is spaced rearwardly with respect to the front registration member along the insert feed direction, which is defined as a general direction from the backstop member toward the front registration member.
The insert hopper further comprises a bottom support plate having a front edge and mounted on the support deck. The bottom support plate has an outer surface on which a lowermost insert of the insert stack is disposed. The outer surface is constructed of a low-friction material such as PTFE, chrome, or finished stainless steel. The front edge of the bottom support plate and the front registration member cooperatively define in insert hopper bottom opening through which the lowermost insert can be extracted in the insert feed direction.
In a further embodiment according to the present invention, the outer surface of the bottom support plate is constructed of a low-friction material which exhibits a coefficient of friction less than a coefficient of friction exhibited by a conventional material such as a cold-rolled steel plate.
In another embodiment according to the present invention, an insert hopper is provided for storing a stack of inserts and enabling seriatim extraction of the lowermost insert of the insert stack from a lower location of the insert hopper along an insert feed direction. A support deck is disposed in a plane and defines a lower boundary of an insert hopper area in which the insert stack can be loaded. A front registration member extends upwardly in relation to the support deck and defines a front boundary of the insert hopper area, and further defines an insert hopper bottom opening through which the lowermost insert of the insert stack can be extracted. A backstop member extends upwardly in relation to the support deck and defines a rear boundary of the insert hopper area. The backstop member is spaced rearwardly with respect to the front registration member along the insert feed direction. A wedge block is mounted on the support deck and has an insert support surface. The insert support surface supports a trailing edge of the lowermost insert and extends into the insert hopper area. The insert support surface is angled with respect to the plane.
In yet another embodiment according to the present invention, a mail insertion machine is provided. The mail insertion machine comprises an insert hopper and an insert extraction device. The insert extraction device is adapted to cyclically move into engagement with a lowermost insert of an insert stack loaded in the insert hopper, and to extract the lowermost insert from the insert hopper. The insert hopper includes a bottom support plate having an outer surface constructed of a low-friction material as described hereinabove.
In a further embodiment according to the present invention, a mail insertion machine is provided and comprises an insert hopper and an insert extraction device. The insert hopper includes a wedge block as described hereinabove.
The present invention additionally provides a method for increasing the capacity of an insert hopper to hold and register a stack of inserts loaded into the insert hopper for subsequent improved extraction from the insert hopper. The insert hopper is constructed by providing a support deck, a front registration member and a backstop member. A bottom support plate is also provided. The bottom support plate has an outer surface on which a lowermost insert of the insert stack is disposed. A front edge of the bottom support plate cooperates with the front registration member to define an insert hopper bottom opening through which the lowermost insert can be extracted from the insert hopper in an insert feed direction. The friction of the bottom support plate is reduced by providing a low-friction material for the outer surface. The low-friction outer surface is constructed of PTFE, chrome, or finished stainless steel.
In another method for improving an insert hopper according to the present invention, the insert hopper is constructed by providing a support deck, a front registration member, and a backstop member. A wedge block is provided, and has an insert support surface angled with respect to the plane. The wedge block is mounted on the support deck, whereby the insert support surface extends into an insert hopper area of the insert hopper to support a trailing edge of a lowermost insert of an insert stack loaded into the insert hopper.
It is therefore an object of the present invention to provide an insert hopper capable of operating with an increased working stack height without impairing the operation of an associated insert extraction device.
It is another object of the present invention to provide an insert hopper in which the lowermost insert of an insert stack loaded into the insert hopper is consistently and properly registered within the insert hopper, such that the lowermost insert is aligned with an insert extraction device and misfeeds are prevented.
It is yet another object of the present invention to reduce the coefficient of friction between the bottom support plate of an insert hopper and the lowermost insert of an insert stack loaded in the insert hopper.
It is a further object of the present invention to provide an improved insert hopper wherein a greater number of inserts to be loaded therein, and inserts can be fed from the insert hopper over a longer period of time before the insert hopper must be reloaded.